bug：float calculation cause deviation

[hcg2008]

in src/native/windows.rc:

unsafe fn update_dimensions(&mut self, hwnd: HWND) -> bool {
....
        let window_width = ((rect.right - rect.left) as f32 / self.window_scale) as i32;
        let window_height = ((rect.bottom - rect.top) as f32 / self.window_scale) as i32;

        // prevent a framebuffer size of 0 when window is minimized
        let fb_width = ((window_width as f32 * self.content_scale) as i32).max(1);
        let fb_height = ((window_height as f32 * self.content_scale) as i32).max(1);
        if fb_width != d.screen_width || fb_height != d.screen_height {
            d.screen_width = fb_width;
            d.screen_height = fb_height;
            return true;
        }

example:
window height : 600, scale :1.75

let window_width = ((rect.right - rect.left) as f32 / self.window_scale) as i32; [<-- 342]
let fb_height = ((window_height as f32 * self.content_scale) as i32).max(1); [ <-- 598 ]

d.screen_height will been assigned 598